1. Field of the Invention
The present invention relates to a device for coating a photosensitive film on a printing plate shaped in a roll (hereinafter called a "plate roll") and more specifically to a device wherein a pretreatment, a photosensitive film coating treatment and a protective film coating treatment are successively performed on the plate roll by a single device.
2. Prior Art
Generally, in a plate making process for a plate roll, steps of BALLARD COPPER plating, buffing, pretreatment, photosensitive film coating, protective film coating, argon ion laser exposure, development, etching, resist stripping, and chrome plating are performed in the order listed.
In the plate making processes described above, the protective film coating is performed for the following reasons: since the photosensitive film uses an ultra-high-sensitivity photosensitive agent which can be exposed by means of an argon ion laser, the photosensitive film is susceptible to oxidation in a short time following the coating. If the photosensitive film is oxidized, the film loses its photosensitivity. Furthermore, if the photosensitive film is exposed in the open air, the oxygen in the air hinders the photosensitive performance of the photosensitive agent.
As is mentioned above, plate making process is comprised of several different steps, and these steps are performed by devices which are lined up independently.
In other words, to make a plate roll, several devices are required. Therefore, the conventional devices occupy large spaces, and the cost of the devices used for plate making are high. Furthermore, handling of the product between the various devices requires considerable time and labor. Moreover, since the pretreatment is conventionally performed by hand, it is desirable that the pretreatment is integrated with the photosensitive film coating device.